THE USE OF MATHEMATICAL AND COMPUTER-MODELS TO EXPLORE THE APPLICABILITY OF FLUIDIZED-BED TECHNOLOGY FOR HIGHLY EXOTHERMIC CATALYTIC REACTIONS .2. OXIDATIVE DEHYDROGENATION OF ETHYLBENZENE TO STYRENE

A model based on the two phase theory of fluidization is developed for the catalytic gas-phase oxidative dehydrogenation of ethylbenzene to styrene in a fluidized bed reactor. The model takes into account the change in number of moles accompanying the reaction taking place in the dense phase. The system exhibited multiple steady states. An optimization search indicated that a maximum styrene production rate can be obtained at an oxygen/ethylbenzene feed ratio of 0.39 and a dense phase temperature of 820 K. A parameteric sensitivity analysis, including a bifurcation study, showed that this optimum steady state operation can be achieved by operating the reactor nonadiabatically with a feed temperature of 410 K and a catalyst particle diameter of 100-mu-m. Under these conditions the operating steady state would be an unstable one.